Invention Grant
- Patent Title: Wide angle variable neutral density filter
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Application No.: US15916115Application Date: 2018-03-08
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Publication No.: US11543669B2Publication Date: 2023-01-03
- Inventor: Gary D. Sharp , Anthony D. McGettigan
- Applicant: META PLATFORMS TECHNOLOGIES, LLC
- Applicant Address: US CA Menlo Park
- Assignee: META PLATFORMS TECHNOLOGIES, LLC
- Current Assignee: META PLATFORMS TECHNOLOGIES, LLC
- Current Assignee Address: US CA Menlo Park
- Agency: Greenberg Traurig, LLP
- Main IPC: G02B27/28
- IPC: G02B27/28 ; G02B5/20 ; G02B5/30 ; H04N5/225

Abstract:
A three (or more) polarizer arrangement is used to demonstrate a wide-angle variable-neutral-density (VND) filter that has both contrast uniformity and color uniformity. According to one embodiment, the outer polarizers effectively counter-rotate with respect to a fixed center polarizer as a means of compensating for transmission non-uniformity associated with geometrical polarization distortions experienced by off-normal rays. In particular, the achromatic compensation arrangement enables angle uniformity relative to normal-incidence transmission when the number of stops of attenuation grows large (e.g. 10-stops, or OD3). The filters are useful for cameras or instrumentation allowing mechanical or electromechanical tuning.
Public/Granted literature
- US20180259692A1 WIDE ANGLE VARIABLE NEUTRAL DENSITY FILTER Public/Granted day:2018-09-13
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